The evolution of pellet size and shape during spheronisation of an extruded microcrystalline cellulose paste

- Spheronisation of cylindrical extrudates is probed by interrupted experiments.
- The time to spheronise small batches is proportional to rotational speed−3.6.
- Rod breakage is followed by rounding, with rounding taking ∼85% time.
- Small pellets round off: large particles pass through a dumb-bell stage.
- X-ray microtomography indicates a variation of porosity in pellets.